Impact of gold nanorod functionalization on biocorona formation and their biological implication

Gold nanorods (AuNRs) have distinctive opto-electronic properties, which facilitate their exploitation in various fields, especially biology and medicine. However, their interaction with the biomolecules in the physiological system can cause the formation of a protein corona, composing of a soft and hard layer, which ultimately alters the physiochemical properties, toxicity, and fate of the nanoparticles. Thus, the formation and composition of protein corona on three differently functionalized AuNRs [CTAB-AuNRs (positive), PEG-AuNRs (neutral), PSS-AuNRs (negative)] were studied for the three most abundant proteins in the blood serum namely, human serum albumin, immunoglobulin tG, and transferrin. The variation in protein adsorption, mean hydrodynamic size, and zeta potential were studied for different protein incubation periods (0, 0.5,1, 4, 8,12, and 24 h). The soft and hard corona layers were estimated for the individual proteins and mixture of the three proteins at the time point of maximum protein adsorption (1 h). Finally, in order to study the biological consequence of the coronation of AuNRs, the cell viability and uptake of AuNRs before and after protein corona formation were studied. The formation of IgG corona helped to reduce cellular toxicity, and at the same time, showed improved cell uptake when compared to the respective as-prepared AuNRs, highlighting their application potential for drug delivery applications. (C) 2017 Elsevier B.V. All rights reserved.